Constant air velocity carburetor



L. J. SPRANGER CONSTANT AIR -vELocITY CARBURETOR Sept. 5, 1950 2Sheets-Sheet 1 Filed Oct. 12. 1946 w W v n@ ,i

Sept. 5, 1950 l.. J. SPRANGER coNsTANT AIR VELOCITY cARBuRx-:TOR

2 Sheets-Sheet 2 Filed Oct. 12, 1946 :vaghe/7 te rFig; i53is" adetail:in lsectiongfenlarged, I taken on PatentedtSept. 5, 1950 l. j

TES PATENT OFFICE 'oonsfrAN'T AIR VELOCITY' CARBURE'JJORl lLeonardJQISprangenOakParkJl'l. l

u l .application oeiolieiv 12, 1946, serial No. 702,972

` 'l' vv.I6 claims.v (01261-41) -jzlMy-r invention Lrelates; fingcertainfnovelfeaturesbywhich fto .produce an an axial opening whichextends through an endl effectivefmixture of rfuel'andlai-r foroperation rwall 29 'at-the top end of the tube. Thek top end-oi-ianzyinternal'combustion engine? It includes of the truncated conehead projects slightly intoinzitsconstruction-:means'zfor:increasingtheratio the mixingchamber-When they plunger is in its .offair :towfuel' with-increase inthe'amountof .the uppermost position, the opening around the conegaseous mixture, thereby conducive to increased then beingv closed. Thisplunger, vtogether vwith economy. in consumption.i This."isiaccomplishedits cooperating seat, forms a choke valve which to :aacarburetorembodythe form of. a truncated cone28 seating within by a* mechanismwhich ist simple and dependable will be further explained hereinafter.As shown, f

in its operation. This objective of my vinven- 10 the plunger body ispolygonal in cross section tion'ias Well asi otherslwhich'Will'fher'einafter apso that vspaces lalong its sides'will remain toproi -pearfmay bei attained bya construction of .which vide apassageway"between the plunger and its -arsuggestivefform isvillustrated rin,` the{accom-l surrounding tube. Ports 30 extend through thepariying:drawings;wherein-a w:

Fig'. 'sia sidepelevation'of'itheLcarhureton I 15 enter therethroughintothe tube.A Ata point Fig; satopiplan-viewzthereofg-' .,.Fig.l.3 isa."verticalgsectiom,taken on line 3-3 wall 3| of the fuel chamber isapertured to re- ,of;-Eig.'2 f t 'ceive'a closure plug 32 whichismaintained inA mig. 4` is a'horizontalsection, takenfon line 4 4 placeby a screw threadedv connection. When this ofiig..i3; f i* 20 plug isremoved, the tube 2D may be passed end'- line 5--5 of Fig. 3; i .i lpermit application of a screw driver wherebyv to Fig. 6 is a viewsimilar to Fig. 3 in which the i rotate the tube eitheryway for purposesof aspartsv-,aregshownas having been| operated to ansembly 'ordisassembly with the mixing charnotherposition; i' 25 berwa1l23.

.,;1?ig.' y7 isa 4view in .perspectivejof the vchoke vThe second tube 2lis alsoclosedat the bottom plunger; and 1 .1: z 'l by an end Wall :35adapted to receive the thrust I\Fig.'.8 is'vaperspectileviewizoftheiieedetubev of coiled spring A36 which extendswithin an leading from thefuel chamber. 1 w y inner tube 31, open at thebottom, but closed AThe ,bodyof the present-carburetoris formed 30 atthe top by an end Wall 38 through which is a tovprovide an airzchamberAin line with a' mixe small'axial opening 39 lying within a cross grooveingchamber M to one 'side of "which is ra' fuel 4D. This inner tube isprovided with'a plurality chamber F. The Walls'deningthesethree chamofsmall portsill` in ystepped formation, close to bers are; suitably,`joined 'torprovide ya :unitary its upper end-and in response tov tensionofthe structure.;` Leading ,into the` iiuel chamber is a 35' springf36the inner tube is vurged upwardly to vfuelpipe I0, andopeningintottheair'chamber project into'the mixing chambergthereby toexis an airt inlet I I. s The;bottomzfofthe*mixing posemore' or lessofits side Wall ports M accordchamber is: open for operative; connectionVwith ing to the distance to which thertube is projected the. intakemanifold (n'otshowni" ofzan'internal axially of itself. Near 'the bottomof thexouter combustion engine. l' ,-.frd 40 tub'e2l, I provide sideWall ports l2v through :i'l'heimw of liquid fuelinto'thefuel chamber iswhich liqudfuel may enter t0 rise' therewthincontrolled by a valve'inthe pipe l0. operated bya To facilitate assemblx7 of the tube 2| 'intoopel"- float l5 Which'is pivotallysup'ported upon a-bar vlli ativeposition.' a second closure plug 43, the same to swing u'p orAdowninispcnse' t fliictuatins asl the plus 32, may 4be removably ttedin the iri the level of' the fuel wlthin'the chamber. By 45 fuel chamber'bottom Wa1113l- `The wa11nassases such a conventional means it'ispo'ss'ibletc keepv wherein the tubes Zrfand 2| are mounted openfs'ub'stntially"constant-level er l ithin the out upon a beveled` seatv45 which-is extended ^f1@a-mber:atiaH-ifgj f 1 crcularly Within themixing chamber A valve i1 'TA-'pair ofltubes 20-and'2l'4areextendedobliq'ue; member linithenforrri fof a-fbeveledfdisk 46 islyfdownwardly ntothei fuels-chamber from .its 50 adapted to fbemovedtoward'and' from this seat wall-"22 which is proximatefto 'themiXine'Cham; and ini al1 of'its. positions to be engaged bythe ber'.Eaclifoffthese tubes 'may be secured by'a upper end38 ofthe inner tube.In the lower sbrew'tthreadeuf"connection/within cylindrical part ofltsftmovementrange this dlsk will also passages which-.extendthiougn'thegwall 22y and remain'y in engagement With' the 'end ofthecone theadjacent wallzBYof thermixingachamber into 55 28 that 1spr'olected fi-omltheunlunger 21; r .Tins communicationwiththeilatterise'e Fig.5).' valvexdisk is carried# by stemflllr Whose lower.zl'h'eitube 2n iSCmSediat;thgbttombyaplug endis slidablyfsupported inAa? tubular guide .48

` {Z5-f against-which isf-'fthrust fthe-lowerlehd .of a which' byapairliofwebs.491is maintained xedly `vcoiled.springzz'tiwhose'upperendresiliently sup- ,y in aCenterpositiorrluarthe-bottom en d of .the'pori-,sia.ZpmUgepQ-Thahglatl-.fits top fa head in 460 mixing :chambenffAe'spring.sfwhich 1sA coiled t tube wall near its'lower end to permitfuel to opposite thel lowerl end of the ltube, the bottom wisetherethrough. liindv slots 33 in the' tube rIhis disk 55 which occupiesan upper positionv relative to the rst valve disk 451 is'beveled on itsunder face for cooperation with a beveled seat 55 which is extendedcircularly inwardly from the surrounding walls to provide a'partialseparation and line of construction between the mixing chamber M belowand the air-"chamberl A above. A limited slip connection between theupper valve disk and the stem is also provided, this taking the form ofa cross pin 51 whichf'is carried by one for engagement within averticaily disposed slot 53 in the other. 1

The tube 54 extends from the upper valve disk upwardly within acylindrical guide wallfithat depends into the air chamber Afrom .atop-Wall El. This guide wall also rises abovethe top wall to furnish aswiveled mounting 'for Vthe cupped end 55 of a lever whieh'is adapted tobe operated by a link connection 57 `from a suitable control (notshown). As Wby l'a set .screwf entered through the cup wall y55"to'tbear' `with pressure against' thetube 56.4 I providefortransmitting rotary motion thereto whenever the lever 55 is operated.A screw 'l5 'which issecured to the tube 54 extends laterally thereof topresent its head within a spiral cam slet il that is formed in the guidewall- 59 (see Fig. 6), so as to cause the tube 54 to be raised orlowered with each operation of the lever 55. By some such means as this,the upper valve disk 55 is moved toward and from its seat 55, the lowervalve disk 45 being also moved in unison therewith. Thefpoint -ofminimum clearance between the valve disk. 5-5and and its seat 55 may bedetermined by a stop 59 thatv is adjustably mounted on the top wall 6lto engage the lever 66 when operated to 'its' limit in a clockwise`direction as viewed in lliig; 2.

To operate the lower valve disk vlll there is slidably positionedthrough the upper end 'I2 of the tube 54 and axially thereof a pin 'l5whose lower end is rested upon the top end of the stem 5l. At its `topend this pin is engaged at I5 by one arm of a bell crank lever 11 whichis pivoted at 18 to the upper end of a bracket 19 that upstands from thetop wall 5| of the air chamber. To the other arm of the bell crank ispivotedy at 8i) an operating rod 8l leading to a suitable control (notshown). By the means just described, I provide for operation of thechoke valve through movement imparted to the stem ell whichwhendownwardly moved will advance the lower valve disk 45 against the seat,the slip movement at the pin and slot connection '57 and 58 permittingthis disk to reach this position even when the upper vaive disk 55 isslightly separated from its seat. l

In operation, when the lever 65 is moved, the stem 4'! will be lifted toraise the valve disk 46 off of its seat. In this movement the plungerhead 28 is permitted to advance outwardly whereby to close the openingthrough the port 29. Concurrentlythe inner tube 31 advances outwardly toexpose additional ports 4i through which liquid fuel is drawn into themixing chamber. Air entering through the opening Il descends into themixing chamber since the valve disk 55 is moved further away fromitsseat when the lever 6B is operated. Under these conditions, a

4 gaseous mixture is produced which, when admitted into an associatedinternal combustion engine, will eiectively support continued operationthereof.

Manifestly when the valve disk 46 is moved away from or toward its seat,the amount of fuel admitted into the mixing chamber is increased ordecreased, respectively; at the same time the `area of the openingaround this valve into the passageway leading to the internal combustionengine is varied, being either increased or decreased as this valvemoves away from or toward its seat. In these operations there is aconstant iniiow of air through the port ll, passing around the valvedisk 55, to enter into the mixing chamber. This inflow varies with theamount of fuel admitted into the mixing chamber since the two valvedisks 55 and 46 operate in unison in their movements toward and fromtheir respective seats. There is accordingly maintained through thecarburetor an air 4movement of constant velocity.

For cold starting, when priming is needed, operation of the control rod8l will produce. a down movement on the stem 41. This will advance bothvalve disks toward their seats, with a slightv overmovement of the valvedisk46 whereby to assure that the plunger head 28 is depressed .belowits normal up position.v By this operation, fuel passing around .theplunger is' admitted through the port 29` into the-'mixing Ichamberwhile inflow of air is greatly reduced through maintaining the valvedisk 55 in a nearlyclosed position. A very rich mixture,` such as is`required under cold starting conditions, ,may laccordingly be producedby the manipulation just described. 'l

I claim:

l. A carburetor in which is comprised a fuel chamber and a mixingchamber,theflatter'having aseat with a valve movable toward and-from thesame, a passageway extending betweenfthe fuel and-mixing chambers andopening out'upon the valve seat of the latter, and a" tube slidablyfitted within the passageway and tension-urged endwise'therein towardthe valve whereby one end portion of the tube normally remains pro#jected into the mixing chamber a distance equal tothe space between thevalve and its seat, and a plurality of ports extended through the tubewalls at points lengthwise thereof proximate to its projected endwhereby to openup communi# cation in varying degrees between the fueland mixing chambers according Ito the distancerof separation between thevalve and 'its seat,"the inner end portion of the ltube being extensibleinto the fuel chamber, and said innerendportion being open at the bottomand in communication with the fuel chamber, saidtube'forming a passagefor fuel from its bottom to .the upper part thereof.

2. A carburetor in `which is comprised a .ifuel chamber and a mixingchamber, the Vlatter having a seat with a valve movable toward and fromthe same, a passageway extending-between the 'fuel and mixing chambersand opening out upon `the valve seat of the latter, and a tube'slidablytted within the passageway and tension-urged endwise therein toward thevalve whereby onevend portion of the tube normallyremains projected intothe mixing chamber a distance equal tothe space between the valve andits seat, the inner end portion of the 'tube'being extensibleintothefuel chamben-and said'innerpend portion being open at the .bottom and incommunicationvwith thefue/lchamber, said tube forming a passage forfuel-from its bottom to the upper part thereof,

and a plurality of ports extended through `the tube walls at pointsproximate to but progressively spaced from its projected end whereby toopen up communication in varying degrees between the fuel and mixingchambers according to the distance of separation between the valve andits seat.

3. A carburetor in which is comprised a fuel chamber and a mixingchamber, the latter having a seat with a valve movable toward and fromthe same, two passageways extending between the fuel and mixing chambersand both opening out upon the valve seat of the latter, a tube slidablyfitted in one passageway andtension-urged endwise therein toward 'theValve whereby one end portion of the tube normally remains projectedinto the mixing chamber a distance equal to the space between the valveand its seat, the

other end of the slidable tube being extensible into the fuel chamber, aplurality of ports exe tended through the tube walls at pointslengthwise thereof proximate toits projected endvwhereby to open upcommunication in varying degrees between the fuel and mixing chambersaccording tor the distance of separation between the valve and its seat,and a device within the sec-v ond passageway tension-urged toward thevalve for engagement therewithwhen the latter is close to its seat anddisengageable therefrom and closing said second passage when the valveis remote from its seat, the valve when positioned close to its seatacting to close 01T the mixing chamber more or less against the passageof air there- 'through and concurrently depress the device to admit fueltherearound through the second pas- 'ably tted in one passageway andtension-urged endwise rtherein towards the valve whereby one end portionof the tubenormally remains projected into the mixing chamber a distanceequal to the space between' the valve and its seat, the other end of theslidable tube being extensible into the fuel chambenxa plurality ofports extending through the tube walls at points lengthwise thereofproximate to its projected end whereby to open up communication invarying degrees between the fuel and mixing chambers according to thedistance of separation between the valve and its seat, a device withinthe second passageway tension-urged towards the valve for engagementtherewith when the latter is close to its seat and disengageabletherefrom and closing said second passageway when the valve is remotefrom its seat, the valve when positioned close to its seat acting toclose off 'the mixing chamber more or less against the passage of airtherethrough and concurrently depress the device to admit fueltherearound through the second passageway and into the mixing chamber'when the valve is spaced slightly from its seat,

an air chamber inv communication with the mixing chamberand providedwith a valve seat, a

' valve in the air chamber movable toward and sagewayinto the mixingchamber when the valve vis slightly spaced from its seat.

4. A carburetor in which is combined a fuel chamber and a mixingchamber, the latter having a seat with a valve movable toward and fromthe same, a lpassageway extending between the fuel and mixing chambersand opening out upon the valve seat of the latter, a tube slidably ttedwithin the passageway and tension-urged endwise therein towards thevalve whereby one end portion of the tube normally remains projectedinto the mixing chamber a distance equal to the space between the valveand its seat, the other from its seat, and a common operating stem forthe valvesin the mixing |and' air chambers whereby to provide foroperation thereof in unison.

6. A carburetor in which is comprised a fuel chamber and a mixingchamber, the latter lhaving a circular seat with a disc Valve movablerectilinearly toward and from the same, a passageway extending betweenthe fuel and mixing chambers and opening out upon the. valve seat of thelatter, and a tube slidably tted within the passageway andtension-urged' endwise f therein toward the Valve whereby one end porendof the sndabie tube being extensible into the fuel chamber, a pluralityof ports extended through v,the tube walls at points lengthwise thereofproximate toits projected end whereby to open -upv communication invarying degrees betion ofthe tube normally remains `projected into themixing chamber a distance equal to the space between the valveand itsseat, and a plurality of ports extended through the tube walls at pointslengthwise thereof proximate to its projected end whereby to open upcommunication in varying degrees between the fuel and mixing chambersaccording to the distance of separation between the valve and its seat.1

LEONARD. SPRANGERf;

REFERENCES CITED The following references are of record in the raie' of`this patent:

tween the fuel and mixing chambers according to the distance ofseparation between the valve and its seat, an air chamber incommunication with the mixing chamber and partially separated therefromby a constriction providing a valve seat, a valve in the air chambermovable toward and from its seat, and a common operating stem for thevalves in the mixing and air chambers y fwhereby to yprovide foroperation thereof in unison.

5. A carburetor in which iscombined'a, fuel chamberand a mixing chamber,the latter having a seat with a valve'movable toward and from the same,two passageways extending between the fuel and mixing chambers and bothopening out upon the valve seat of the latter, a tube slid- 424,584Greatk Britain Feb. 25, 1935

